Add and update the following features:

* Automation
  - FastClosureCache
    -- Added utility class that improves performance of Fast Closure.
  - SessionStateScopeProxy(proxy class for System.Management.Automation.SessionStateScope)
    -- Fix the bug that NullReferenceException is thrown if an scope has no parent scope.

* Mixin
  - RunspaceMixin(mixin class for System.Management.Automation.Runspaces.Runspace)
    -- Moved the features ScriptBlockMixin had.
  - ScriptBlockMixin(mixin class for System.Management.Automation.ScriptBlock)
    -- Moved the features to RunspaceMixin because there are a lot of informations that are known by only Runspace.
    -- Added the special method to invoke Fast Closure.